Hi Mark,
Overwhelming sibilance on some recordings is one of the downsides of really linear hi-fidelity speakers, because as most everyone knows, they reveal the problems of the source recording, warts and all. If you played the Billy Joel recording on some mediocre car speakers or boombox, it might sound quite good. That, of course, is the reason why some recording engineers goose the midrange so it will have "presence" on small, inadequate playback systems.
It's a terrible practice and kind of a holdover from the era of vinyl, where there were real losses in fidelity that engineers tried to compensate for by boosting the mids and highs--and sometimes the bass. You reminded me of an early Billy Joel CD I owned that was horribly sibilant, so much so that I didn't put it into my mega-changers because I found it unlistenable.
Plus you never know what "monitors" a recording is mixed with. If the playback monitors in the control room have a midrange dip, then the engineer will boost the midrange to compensate and that will sound grating and sibilant on a linear system.
Alan
